Mactenn Systems Ltd

Mactenn Systems Ltd specialise in high quality, low-velocity, dense phase pneumatic conveying systems. Their pneumatic conveying systems are used worldwide in various process industries handing a diverse range of bulk materials. They are a sister company of Macawber Engineering Inc. in the US that has focused on pneumatic conveying for over 40 years. Mactenn is known for their expertise as well as the reliability of their technology. 

Mactenn Systems Ltd's high quality range of pneumatic conveyors includes:

  • Maxflo
  • MultiAshflo
  • Cementveyor
  • MiniMaxflo
  • Macpump and many more
  1. Hot Stuff! High Temperature valve for Dense-Phase Conveying and more
    30 January 2020

    One of the notable features of Mactenn (a sister company of Macawber Engineering Inc. in the US) pneumatic conveying systems is their ability to handle hot materials. We first encountered hot material applications in the foundry industry. A common application is the handling of hot knock-out sand (the remains of the sand mold after the hot metal has been poured and the casting made) which could reach temperatures of 350-400C°.

    The problem with transporting hot material of this nature had always been an effective filling valve that would perform well in these high temperatures. To address this need we added to our Inflatek® Valve range a design that could operate at high temperatures without impairment of performance. Our standard Inflatek® Valve operates up to 100C° without any change to its design, and special seals can increase this range to 200C°. To be able to exceed 200C°, we designed our valve to include water cooling up to 350C°. Today this added capability enables us to address many different and difficult materials handling applications not just within the foundry industry but also in the petrochemical and other industries.

    Hot Stuff! High Temperature valve for Dense-Phase Conveying and more
  2. Fly Ash Pneumatic Conveying Systems, Poland
    30 January 2020

    Two Mactenn fly ash dense-phase pneumatic conveying systems were supplied to convey 30t/h each over a distance of up to 385 meters horizontally and 36 meters vertically. The ash systems are designed to convey 31,500 Kg/h of ash. Both conveying systems are located under a feed hopper with start and stop controlled in automatic by the feed hopper and silo reception level probes. The fly ash systems are working very reliably with no line blockages and exceed the customer’s expectation regarding transfer rate and performance. These particular Mactenn systems incorporated multiple manifold settings allowing the transfer of a range of fly ash products over various distances. The final convey air requirement on the longest route was 760 scfm compared to the proposed 988 scfm resulting in a saving both in cost and air used from the compressed air system. One particular problem was a very low control air pressure resulting in a compromised sealing of the Inflatek Valve inflatable seal. This was overcome by installing a pressure doubler and small air reservoir to provide more than sufficient instrument air pressure and excellent sealing.

    SYSTEM OBJECTIVES

    • Dense phase low velocity conveying
    • Reliable operation.

     

    IMPROVEMENTS ACHIEVED

    • Increased transfer rate
    • Cost savings: reduced compressed air requirements 3. Increased reliability compared to older system.

    For more information please contact Mactenn.

    Fly Ash Pneumatic Conveying Systems, Poland
  3. Service Life of Dense Phase Pneumatic Conveying
    30 January 2020

    The dense phase pneumatic conveying system was supplied to convey 14 t/h of sodium bicarbonate over a distance of 8m horizontal and 30m vertical. The system is a 228 liter Maxflo with a 125mm pipe line and is located under a feed hopper with start and stop controlled in automatic by the feed hopper and silo reception level probes. The system was first installed in November 1996. In July 2014 after 17 years of continuous daily operation it was upgraded with a touch screen operator interface, new filling Inflatek® Valve and air manifold. The vessel and pipe line remain originals and are in very good condition expected to offer many more years of service. The pipe line, bends, and vessel are made from stainless steel 304 with all external surfaces coated in a corrosive resistant clear lacquer.

    Please click here for further information 

    Service Life of Dense Phase Pneumatic Conveying
  4. Mactenn Announces Collaboration with Lysair
    30 January 2020

    Mactenn is proud to announce that Lysair Air Solutions will become the exclusive representative of Mactenn in Belgium, the Netherlands, and Luxembourg. They will also be the non-exclusive representative in France.

    Lysair will develop the market for dense phase pneumatic conveying systems in Benelux and France. The parties will combine forces; Lysair will add scope to its existing offering by including Mactenn’s dense-phase equipment such as pressure vessels and Inflatek® Valves.  Lysair will in turn provide fabrication of the additional materials such as piping, filters, etc. as well as equipment installations.

    Mactenn is pleased to have the opportunity to co-operate with Lysair. Mactenn's product range is complimentary to Lysair's. Lysair is known for it's strength and know-how in dilute phase pneumatic transport and dust handling installations, providing high quality solutions.

    Lysair specializes in techniques destined for environmental conservation developing and producing installations for industrial de-dusting, pneumatic transporters and flue gas scrubbing.

    Lysair offers a wide range of products including:

    • Piping and Ducting in Steel
    • Stainless Steel
    • Galzanized Steel
    • Fans
    • Filters
    • Scrubbers for wet and dry applications
    • Rotary valves

    We look forward to this collaboration and welcome them to the team.

    Contact Lysair at www.lysair.co

    Mactenn Announces Collaboration with Lysair
  5. Mactenn Design Philosophy
    30 January 2020

    1.Dense phase pneumatic conveying pressure vessels were introduced to the U.S. markets in the early 1960’s.  Pressure vessels were used because the pressures required for dense phase conveying normally exceeded 15 psig – the limit at that time for rotary airlock valves which were used almost exclusively by manufacturers of positive pressure dilute phase systems. In order to accommodate the higher pressures necessary for dense phase conveying systems,  ASME coded vessels became mandatory.

    2.The valves available at that time for use as in-feed to pressure vessels were limited to butterfly valves although slide gates were also tried.  There are several problems associated with butterfly valves and slide gates when used as pressure vessel in-feed valves:

    • Butterfly and slide gates valves are not able to cut through a falling or static column of material since the material is trapped between the valve disc and the seat preventing effective sealing when the vessel is pressurized. Two valves must be used – one above the other.  The upper valve cuts off material flow but does not seal.  The lower valve then closes properly and seals effectively.  (A level probe is necessary in the vessel to sense when the upper valve must close.)
    • When butterfly valves are open, the valve discs are directly in the flow of material. This not only inhibits flow into the vessel, but also makes the valve susceptible to wear, even with mildly abrasive materials.  The valve deteriorates at an increasing rate and sealing again becomes ineffective.  Often, the valve fails altogether.
    • To avoid poor sealing, the valves must be continuously maintained and often completely replaced – even as frequently as every 2-3 months.

    3.To reduce the above effects on the valve, the pressure vessels are designed to cycle infrequently – usually 10 to 12 times per hour.  This reduces the load on the butterfly and/or slide gate valves and extends their wear life.  This means, however, that quite large vessels are used.  For example, a vessel of 15 to 25 cu.ft. conveying through a 4” line is quite common.

    4.When the pressure vessel cycles, the material in the vessel is forced out into the pipeline due to the pressure of the air and entrainment of the material with air.  With the arrangement described in item 3 above all of the material would be forced into the pipeline as a single plug of material, which would be 175 to 250 ft. long depending on the size of the vessel.  The pressure required to transport such a plug would be higher than the available output of a standard compressor, resulting in a blocked pipeline.

    The manufacturers of these systems avoid this possibility by “conditioning” the material.  Conditioning typically takes place in the pipeline in the form of pipe line air injectors, sometimes referred to as “boosters”.  The effect of conditioning is to dilute and break up the plug and maintain a high enough velocity to prevent blockages.  Unfortunately, the addition of air through the boosters often causes increased material velocity far in excess of that desired.  The effects of such high velocities are high wear rates on pipelines, high particle attrition,excessive air consumptions and, in spite of the boosters, the risk of a blocked line.

    5.Macawber realized that to avoid blockages, the necessity of boosters, high air consumptions and high material velocities, it would be necessary to reduce the plug length in the pipeline.  It was found, through testing, that a plug length in the range of 40 to 60 ft. would convey at low velocity and with low air consumption using pressures in the 15 to 40 psig range.

    6.To produce such short plugs would require small vessels and this, in turn, would require frequent cycles to maintain the desired conveying rate (40 to 80 cycles/hour normally).  Clearly butterfly valves are not going to be suitable to address these requirements.  Macawber solved this problem by developing the Inflatek Valve.  The Inflatek Valve can close through a column of material and seal effectively.  The seal is pneumatic and inflates only when the valve is closed.  The air pressure in the seal is 80 to 100 psig exceeding the vessel conveying pressure by at least 30 psig.  The valve, when open, has no restrictions while filling, and the valve is robustly designed to minimize inspections.  Maintenance time and costs are extremely low.

    7.In addition to being able to convey materials at low velocity, the Maxsflo offers other advantages:

    • Low profile - easier to accommodate under silos, bulk bag unloaders, reclaimers, etc. Silo heights can be reduced thereby reducing  structural support costs.
    • Easier to install.
    • Quicker vessel filling times.
    • Smaller filter units (for exhaust air).
    • No pipeline air injection systems required – less installation – less equipment to maintain.
    • Easier access for inspection.
    • Standard schedule 40 pipelines are used.
    • One year no-wear guarantee on pipeline components.
    • Low power requirements as a result of low air consumption.

    The Macawber Design Philosophy has been applied to a wide and diverse range of materials in almost every process industry.  This advanced process of pneumatic conveying has been refined and developed since its introduction in 1977 and continues to be successfully applied in thousands of installations worldwide.

    Mactenn Design Philosophy
  6. Blocked Pipelines? No problem for Mactenn
    30 January 2020

    What are the reasons for blocked conveying lines?

    All pneumatic conveying systems block sometimes.  Clearing a pipeline means downtime, loss of production and can be a maintenance headache so ensuring your system runs as smoothly as possible day after day is critical. Here at Mactenn we have been designing pneumatic conveying systems for years using our knowledge and experience to design systems that aim to provide the most reliable and maintenance free systems possible.  We do not like blockages or any other maintenance issues any more than you do but if they do happen, understanding where to look to minimize downtime is essential.  Here are some pointers for a quick recovery:

    1. Machine Settings – Settings of the system should remain as set during start-up. However in practice they are often modified intentionally or unintentionally during maintenance or in order to overcome an upset condition. Incorrect settings can create material blockages.

    2. Changes to controls – Sometimes it is essential to modify PLC programming. For instance, adding additional distribution valves, changing the requirements of the weighing system, changing the number of and/or weight of ingredients for a mixer charging system.  Any control changes should be carried out in conjunction with the system manufacturer.  If not, the customer may inadvertently change some of the basic settings, times etc. fundamental to the operation of the pneumatic conveying system.

    3. Out-of-Specification Material – Has your material changed? Is the bulk density, particle size distribution and flowability what the system was designed for? If the answer is no, the blockages could be explained by the material.  

    4. Foreign Material – Sometimes foreign objects such as used welding rods, cigarette packs, wire, nuts and bolts, etc. find their way into the silo/feed hopper etc.  As these materials accumulate they create a blockage preventing the conveyed material from entering the conveying line or moving along down the pipeline.

    5. Moisture in the conveying process - Moisture can change the material characteristics. Materials will become sticky or poorly flowing resulting in conveying blockages. For instance, with baghouse and ESP installations there is the possibility that water or steam may enter the hoppers e.g.,  due to a faulty boiler tube/s.  As most types of ash are hygroscopic (they absorb moisture from their surroundings) moisture will change the consistency of the ash and create conveying difficulties.

    6. Air Supply Problems - If the air supply to the conveying system has inadequate pressure, flow and/or contains too much moisture, this can cause the material to slow down in the pipe line. Usually this causes the pressure to rise and if the air supply pressure cannot be maintained through the cycle, the system will block

    7. Pipe Line Incorrectly Installed – Any changes to the original pipe route configuration can cause blockages. If you have a need to modify a pipe route contact the supplier for verification or for re-configuration and resizing of your system.

    8.  Recieving Bin High Level Probe Failure- Check the operation of the level probes if fitted. Level probes are installed to       signal the system that the receiving bin is full (i.e. when the probe is contacted by material) and to shut the system down until the probe is uncovered. Faulty level probes may allow the system to keep on conveying material to the bin/silo and over fill it. If not noticed by the operating personel, the sytem will continue to convey, gradually filling the pipeline until it blocks.

    9. Defective Components- Faulty components such as pressure regulators, solenoid valves, etc., can result in failure of the conveying air supply leading to pipeline blockages.

    The good news is that most problems can be solved by a simple phone call to our Service Department and it is free.  

    To find out more please contact us at Mactenn

    Blocked Pipelines? No problem for Mactenn
  7. Another 3-way Diverter Valve Tested Successfully
    30 January 2020

    We have successfully tested another 250 mm Stainless Steel 3-way T-Type Diverter Valve to be used for conveying fish food. The Diverter Valve is designed to be used in dense-phase pneumatic conveying applications for handling fragile materials minimising material breakage. The diverter valve is also available in the US via our sister company Macawber Engineering

    Another 3-way Diverter Valve Tested Successfully
  8. Dense Phase Pneumatic Conveying and Its Benefits
    27 January 2020

    Dense phase pneumatic conveying is best described as using the lowest attainable material velocities to ensure the majority of material remains below the saltation level. It is a simple, efficient, cost effective and safe mode of transport particularly beneficial for handling difficult to convey materials.

    What are the benefits of dense phase pneumatic conveying?

    *Low air/energy consumption (cyclical and autonomous functionality)

    *Minimal material degradation

    *Low pipeline and component wear

    *Fewer maintenance points

    *Capable of handling abrasive materials

    *Capable of handling fragile materials

    *Enviromentally friendly;no material spillage, no dust emission, low noise emission

    Dense Phase Pneumatic Conveying and Its Benefits

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